type Person = {
    name: string
    friend?: {
        name: string
        age?: number
    }
}

const info: Person = {
    name: "yzh",
    friend: {
        name: "kobe",
        age: 18
    }
}


console.log(info.name);
console.log(info.friend);
console.log(info.friend?.name);
console.log(info.friend?.age);



export {}